with a gas chromatograph hyphenated with a mass spectrometer. For that purpose, we have devised an automated liquid transfer setup comprising a peristaltic pump, control unit, customized transfer vial with a drain port, and an autosampler arm to deliver liquid extract aliquots at defined time points. The on-line SDE-GC/MS system enables one to record real-time extraction profiles. These profiles reveal extraction kinetics of various VOCs present in the extracted samples. The data sets were fitted with the first order kinetic equation to obtain - 1 numeric values characterizing the extraction process (rate constants ranging from 0.21 to 0.01 min for the ethyl esters from C to C ). A comparison of on-line and off-line results reveals that the on-line system is more 6 19 dependable, while the off-line analysis leads to artifacts. To demonstrate the operation of the on-line SDE- GC/MS system, we performed analyses of selected real samples (beer). The real-time data sets revealed extraction kinetics for VOCs present in these samples. The devised extraction-analysis system allows the analysts to make an evidence-based decision on the extraction time for different groups of analytes in order to maximize extraction yield and minimize analyte losses.

Lin, K., Huang, X., Zhao, Y.-P., 2019. Combining image recognition and simulation to reproduce the adsorption/desorption behaviors of shale gas. Energy &Fuels 34, 258-269.

https://doi.org/10.1021/acs.energyfuels.9b03669 Shale gas stored in deep shale is in a supercritical state. Therefore, it is necessary to study the adsorption and desorption properties of supercritical shale gas. To accurately determine the state of methane (CH ) in the pores 4 of deep shale, the fractal characteristics of several shale samples drilled at a depth of 2650 mare analyzed using scanning electron microscopy (SEM) and image analysis. We find nanopores with different fractal features in the shale. The effects of adsorption energy and substrate strain on adsorption capacity are clarified. The virial coefficients of CH are obtained by molecular dynamics (MD) simulations and are consistent with the 4 experiment. The adsorption and desorption of CH in different fractal nanopores are modeled using grand 4 canonical Monte Carlo (GCMC) simulations at different temperatures and pressures (from capillary condensation to supercritical state). Additionally, the gas-in-place (GIP), excess adsorption, and absolute adsorption isotherms are obtained. We find the crossover of excess adsorption isotherms, which was observed in the experiment, and the absolute adsorption amount increases with the increase in pressure in the case of ultrahigh pressure (>40 MPa). Moreover, we obtain an ultrahigh-pressure dual-site Langmuir equation, and it can accurately describe observed adsorption isotherms from low pressure to ultrahigh pressure. Our study visually reproduces the adsorption/desorption behaviors of CH under in situ conditions in deep shale and 4 reveals their microscopic mechanism.

Lin, X., Huang, M., Chen, H., Wang, J., Wang, R., 2019. Influence of different polar solvent extraction on pore structure in shale. Acta Petrolei Sinica 40, 1485-1494.

http://www.syxb-cps.com.cn/EN/abstract/abstract5796.shtml Shale's pore type and structure will directly affect the occurrence and production of gas. To discuss the effect of soluble organic matters in shale on the pore structure, different polar soluble organic matters in the shale are separated and extracted in the order of n-hexane, dichloromethane and tetrahydrofuran. Further, using the field emission scanning electron microscope (FE-SEM)and low-temperature nitrogen adsorption tests, this paper comparatively analyzes the pore structure characteristics of original sample and raffinate, and explores the effects of different polar solvent extraction on the pore structure of shale. The results show that with the increasing of organic solvent polarity, the soluble organic matters in shale are dissolved in the order of saturated hydrocarbons, aromatic hydrocarbons and non-hydrocarbon components. The original pores mainly include four types:intergranular pores, intragranular pores, organic pores and micro-cracks. After the soluble organic matters are dissolved, the pore morphology is more irregular, thus forming more dissolved pores; some intergranular pores are filled with the detached debris. Solvent polarity is enhanced, the area of hysteresis loop is reduced, and the BJH pore volume and average pore size are increased, accompanied by insignificant change in the BET specific surface area. The dissolution of soluble organic matter has the effect of "enhancing pores" and "expanding pores" on shale, with the increased pore content ≤ 2 nm and relatively decreased pore cont ent>2 nm. In the mesopore range, the percentage content of pore volume and specific surface area is decreased in the pores of 2-10 nm, with insignificant change in the pore size range of 10-30 nm and significant increase in the